1. Field of the Invention
The invention relates generally to cathode ray tube display terminals and more specifically to the protection of the logic board during shipment and during normal operation of the terminals, thereby allowing customer replacement of the logic board without damage to the logic board or injury to the customer.
2. Description of the Prior Art
Many data processing systems include a cathode ray tube (CRT) display terminal in the system console. The operator uses the terminal to verify information before inserting the information into the system or to display information received from the system. The logic for controlling the CRT display terminal is included in the system console logic and is accessible to field maintenance personnel only.
Many more recent data processing systems include CRT display terminals coupled to communication lines. These terminals are installed at offices remote to the data processing system. Field maintenance personnel travel to the remote site to repair defective terminals. To reduce the maintenance cost, terminals are built with a modular construction enabling customer personnel to replace defective modules.
CRT display terminals, typically the IBM 3101, are built in two sections, one section including a power supply, miscellaneous switches and a logic board; and the other section including the cathode ray tube with its associated circuitry. Here customer personnel replace either section. Each section, however, is relatively complex and costly.